Methods of treating or preventing periodontitis and diseases associated with periodontitis

ABSTRACT

The present disclosure describes methods for preventing or treating periodontitis or diseases associated with periodontitis. The present disclosure also describes methods of screening for compounds that can be used to prevent or treat periodontitis or diseases associated with periodontitis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit under 35 U.S.C. 119(e) to U.S.Application No. 61/662,022 filed Jun. 20, 2012.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with government support under Grant No. DE021685awarded by National Institute of Dental and Craniofacial Research(NIDCR), a National Institutes of Health. The government has certainrights in the invention.

TECHNICAL FIELD

This disclosure generally relates to periodontal disease and methods oftreating or preventing periodontitis.

BACKGROUND

Periodontitis is a prevalent chronic inflammatory disease that leads tothe destruction of the tissues that surround and support the teeth(periodontium). This oral disease is initiated by bacterial biofilms,which form on subgingival tooth surfaces and comprise mostly communitiesof gram-negative anaerobic species. The host inflammatory response tochronic microbial challenge at the dentogingival niche is implicated ininflicting damage upon the periodontium.

Although traditionally perceived as an antimicrobial enzyme system inserum, complement is now recognized as a central component of hostdefense impacting both innate and adaptive immunity. Not surprisingly,given its importance in fighting pathogens, complement constitutes a keytarget of immune evasion by microbes that cause persistent infections.

SUMMARY

The present disclosure describes methods for preventing or treatingperiodontitis or diseases associated with periodontitis. The presentdisclosure also describes methods of screening for compounds that can beused to prevent or treat periodontitis or diseases associated withperiodontitis.

In one aspect, a method of treating or preventing periodontitis ordiseases associated with periodontitis in an individual is provided.Such a method generally includes administering a compound to theindividual that inhibits or blocks C3 expression, activity, oractivation. Representative compounds include, without limitation,compstatin, analogs of compstatin, complement receptor 1-relatedgene/protein y (Crry), and complement activation blocker-2. Anotherrepresentative compound is an antibody against C3, or, for example, apeptidomimetic antagonist of C3. Representative diseases associated withperiodontitis include, without limitation, atherosclerosis, diabetes,osteoporosis, and pre-term labor.

In another aspect, a method of reducing the amount of Porphyromonasgingivalis and/or the inflammation caused by P. gingivital in anindividual is provided. Such a method generally includes administering,to the individual, a compound that inhibits or blocks C3 expression,activity, or activation. Representative compounds include, withoutlimitation, compstatin, analogs of compstatin, complement receptor1-related gene/protein y (Crry), and complement activation blocker-2.

In still another aspect, a method of screening for compounds that treator prevent periodontitis or diseases associated with periodontitis isprovided. Such a method typically includes contacting a cell, in thepresence of P. gingivalis, with a test compound; and evaluating the cellfor expression, activity, or activation of C3. Generally, a reduction inthe expression, activity, or activation of C3 in the presence of a testcompound is indicative of a test compound that can be used to treat orprevent periodontitis or diseases associated with periodontitis. In someembodiments, the cell is a mammalian cell. In some embodiments, the cellis a recombinant cell comprising an exogenous nucleic acid encoding C3.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which the methods and compositions of matter belong. Althoughmethods and materials similar or equivalent to those described hereincan be used in the practice or testing of the methods and compositionsof matter, suitable methods and materials are described below. Inaddition, the materials, methods, and examples are illustrative only andnot intended to be limiting. All publications, patent applications,patents, and other references mentioned herein are incorporated byreference in their entirety.

DESCRIPTION OF DRAWINGS

FIG. 1 is graphs showing that C3 deficiency protects againstinflammatory periodontal bone loss. FIG. 1A is a graph showingperiodontal bone levels. FIG. 1B reveals relative mRNA expression levelsfor the cytokines interleukin-1 beta (IL-1β), tumor necrosis factoralpha (TNF-α), interleukin 6 (IL-6), and interleukin 17A (IL-17A). FIG.1C demonstrates the protein levels of IL-1β, TNF-α, IL-6, and IL-17A ingingiva extract. Data are means±SD (n=5 mice). P<0.05 and **, P<0.01 vs.sham-infected WT, significant (p<0.01) inhibition of bone loss orcytokine induction. Key: W-S: WT & sham-infected; W-P: WT & Pg-infected;C3-S: C3−/− & sham-infected; C3-P: C3−/− & Pg-infected.

FIG. 2 is a graph showing the colonization and effects of P. gingivalisin the periodontium of normal or complement-deficient mice. Data aremeans±SD (n=5 mice per group). *P<0.01 between the indicated groups.

FIG. 3 are graphs showing bone loss measured in defleshed maxillae(Panel A) and mRNA expression of the indicated cytokines (normalizedagainst GAPDH mRNA) and expressed as fold change in the transcriptlevels in the ligated site relative to those of the contralateralunligated site (assigned an average value of 1; Panel B). Data aremeans±SD (n=5 mice). Negative values indicate bone loss relative to theunligated contralateral tooth. *, P<0.01 vs. WT control. •, significant(P<0.01) inhibition of cytokine induction.

FIG. 4 are graphs showing that Cp40 decreases inflammatory clinicalparameters of NHP periodontitis. FIGS. 4A, 4B, 4C, and 4D show resultsfor probing pocket depth, gingival index, bleeding on probing, andmobility index, respectively, which are measurements typically used todetect clinical periodontal inflammation and bone lose. FIG. 4Erepresents a radiograph measurement of bone height. Starting 3 daysafter initiation of ligature-induced periodontitis, Cp40 (500 μg) wasinjected locally into the maxillary interdental papillae from the 1^(st)premolar to the 2^(nd) molar, in two animals, three times weekly. Aninactive analog of Cp40 (control) was injected into the contralateralside of the mouth in the same two animals (split-mouth design). Shownare the effects of Cp40 on the indicated inflammatory clinicalparameters and bone heights, determined using standardized X-ray images(taken at week 6) and NIKON imaging system software. Specifically, thedistance between the cement-enamel junction (CEJ) and alveolar bonecrest (ABC) was measured at six points (1^(st) premolar, distal; 2^(nd)premolar mesial & distal; 1^(st) molar, mesial & distal; 2^(nd) molarmesial) and the data in Panel E reflect the 6-site total. The higherCEJ-ABC distance values of the controls as compared to those of Cp40treatments signify increased bone loss in the absence of drug treatment.In all animals, the gingival margin was at the cement-enamel junction,and thus, PPD readings equaled clinical attachment loss (CAL).

FIG. 5 are graphs showing that Cp40 inhibits proinflammatory cytokineproduction and osteoclastogenesis in NHP periodontitis. Specifically,the panels show the relative protein levels for TNF (FIG. 5A), IL-1b(FIG. 5B), IL-6 (FIG. 5C), IL-17A (FIG. 5D), receptor activator ofnuclear factor kappa-B ligand (RANKL; FIG. 5E), and osteoprotegerin(OPG; FIG. 5F). At the same timepoints that clinical exams wereperformed (as per FIG. 4), GCF was collected from the same monkeys(treatment details in FIG. 4 legend) using PERIOPAPER absorbent stripsto assay the indicated cytokines. Total cytokine content in the elutedGCF samples was measured using MILLIPLEX MAP (multi-analyte panels) kitson a BIO-PLEX detection system. In Panel G, TRAP-positive multinucleatedcells (osteoclasts) were enumerated in nine serial sections for eachbone biopsy specimen taken between the 2^(nd) premolar and 1^(st) molarof each animal.

FIG. 6 are graphs showing a significant inhibition of inflammatoryclinical parameters following treatment of NHP periodontitis with Cp40.Panels A, B, C, and D show measurements for probing pocket depth,gingival index, bleeding on probing, and mobility index, respectively,between Cp40 treated and control animals. Starting 3 days afterinitiation of ligature-induced periodontitis, Cp40 (500 μg) or controlwere injected locally into the mandibular interdental papillae from the1^(st) premolar to the 2^(nd) molar, three times weekly, in oppositessides of the mouth (split-mouth design). The effects of Cp40 weredetermined on the indicated inflammatory clinical parameters at theindicated timepoints. In all animals, the gingival margin was at thecement-enamel junction, and thus, PPD readings equaled clinicalattachment loss (CAL). Data are means±SD (n=4 monkeys). *, P<0.05; **,P<0.01 vs. control.

FIG. 7 are graphs showing decreased GCF levels of proinflammatorycytokines following treatment of NHP periodontitis with Cp40.Specifically, levels of TNF-α (Panel A), IL-1β (Panel B), IL-6 (PanelC), interleukin 8 (IL-8; Panel D), IL-17A (Panel E), interleukin 18(IL-18; Panel F), granulocyte colony-stimulating factor (G-CSF; PanelG), RANKL (Panel H), and OPG (Panel I) were measured. At the sametimepoints that clinical exams were performed (as per FIG. 6), GCF wascollected from the same monkeys (treatment details in FIG. 6 legend)using PERIOPAPER absorbent strips to assay the indicated cytokines.Total cytokine content in the eluted GCF samples was measured usingMILLIPLEX MAP (multi-analyte panels) kits on a BIO-PLEX detectionsystem. Data are means±SD (n=4 monkeys). *, P<0.05; **, P<0.01 vs.control.

FIG. 8 are graphs showing inhibition of periodontal bone loss followingtreatment of NHP periodontitis with Cp40. Four monkeys were treated asdescribed in the legend to FIG. 6, and their mandibular bone heights(CEJ-ABC distance) were measured using standardized X-ray images (takenat baseline and at week 6) and NIKON imaging system software.Measurements were made at six points (1^(st) premolar, distal; 2^(nd)premolar mesial & distal; 1^(St) molar, mesial & distal; 2^(nd) molarmesial) and the data in Panel A and Panel B reflect, respectively, the6-site total at baseline (Panel A) and at week 6 (Panel B). For eachcontrol or Cp40 treatment, bone loss was calculated as bone height atbaseline minus bone height at 6 weeks (Panel C). The difference betweenCp40 and control was significant (P<0.05; paired t test).

Like reference symbols in the various drawings indicate like elements.

BRIEF DESCRIPTION OF THE BIOLOGICAL SEQUENCES

The following sequences comply with 37 C.F.R. §§1.821-1.825(“Requirements for Patent Applications Containing Nucleotide Sequencesand/or Amino Acid Sequence Disclosures—the Sequence Rules”) and areconsistent with World Intellectual Property Organization (WIPO) StandardST. 25 (2009) and the sequence listing requirements of the EuropeanPatent Convention (EPC) and the Patent Cooperation Treaty (PCT) Rules5.2 and 49.5(a-bis), and Section 208 and Annex C of the AdministrativeInstructions. The symbols and format used for amino acid sequence datacomply with the rules set forth in 37 C.F.R. §1.822.

The amino acid sequences for Compstatin and analogs of Compstatin aredepicted in Table A.

TABLE A Compstatin and Compstatin analogs. Peptide SEQ Name Amino AcidSequence ID NO. Compstatin Ile-Cys*-Val-Val-Gln-Asp-Trp-Gly-His-His- SEQID Arg-Cys*-Thr NO: 1 Peptide VI Cys*-Val-Val-Gln-Asp-Trp-Gly-His-His-SEQ ID Arg-Cys* NO: 2 Peptide VIII Cys*-Val-Ala-Gln-Asp-Trp-Gly-His-His-SEQ ID Arg-Cys* NO: 3 Peptide XIII Cys*-Val-Val-Gln-Asp-Trp-Gly-Ala-His-SEQ ID Arg-Cys* NO: 4 Peptide XIV Cys*-Val-Val-Gln-Asp-Trp-Gly-His-Ala-SEQ ID Arg-Cys* NO: 5 Peptide XV Cys*-Val-Val-Gln-Asp-Trp-Gly-His-His-SEQ ID Ala-Cys* NO: 6 Compstatin-Ile-Cys*-Val-Val-Gln-Asp-Trp-Gly-His-His- SEQ ID NH₂ Arg-Cys*-Thr-NH₂NO: 7 4W9A Ac-Ile-Cys*-Val-Trp-Gln-Asp-Trp-Gly-Ala- SEQ IDHis-Arg-Cys*-Thr-NH₂ NO: 8 4(1MeW)Ac-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Gly- SEQ IDAla-His-Arg-Cys*-Thr-NH₂ NO: 9 Cp10Ac-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-Ile-NH₂ NO: 10 Cp20Ac-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 11 Peptide 1Me-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 12 Peptide 2Gly-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 13 Peptide 3Sar-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ ID (Cp30)Ala-His-Arg-Cys*-mIle-NH₂ NO: 14 Peptide 4Tyr-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 15 Peptide 5Phe-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 16 Peptide 6Arg-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 17 Peptide 7Trp-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 18 Peptide 8Thr-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 19 Peptide 9Tyr(Me)-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp- SEQ IDSar-Ala-His-Arg-Cys*-mIle-NH₂ NO: 20 Peptide 10mPhe-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 21 Peptide 11mVal-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 22 Peptide 12mIle-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 23 Peptide 13mAla-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 24 Peptide 14dTyr-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ ID (Cp40)Ala-His-Arg-Cys*-mIle-NH₂ NO: 25 Peptide 15dPhe-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 26 Peptide 16dTrp-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 27 Peptide 17dCha-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 28 Peptide 18dAla-Ile-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 29 Peptide 19Ac-Trp-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 30 Peptide 20Tyr-Gly-Cys*-Val-Trp(1Me)-Gln-Asp-Trp-Sar- SEQ IDAla-His-Arg-Cys*-mIle-NH₂ NO: 31 Cys* = oxidized cystein residuesoptionally joined together via a disulfide bridge. NH₂ = amidation ofthe C-terminus. Ac = acetylation of the N-terminus. Trp(1Me) =1-methyl-trptophan. Sar = sarcosine (N-methyl-glycine). Me = methylationof the N-terminus. m = methylated amino acid residue. Tyr(Me) =0-methyl-L-tyrosine. d = D-stereoisomer of an amino acid residue. Cha =cyclohexylalanine.

DETAILED DESCRIPTION

Periodontitis is a set of inflammatory diseases affecting theperiodontium, i.e., the tissues that surround and support the teeth.Periodontitis involves progressive loss of the alveolar bone around theteeth, and, if left untreated, can lead to the loosening and subsequentloss of teeth. Periodontitis is caused by microorganisms that adhere toand grow on the tooth's surfaces, along with an overly aggressive immuneresponse against these microorganisms. Periodontitis manifests aspainful, red, swollen gums, with abundant plaque. Symptoms may includeredness or bleeding of gums while brushing teeth, using dental floss, orbiting into hard food (e.g. apples); recurrent swelling of the gum;halitosis and a persistent metallic taste in the mouth; gingivalrecession resulting in apparent lengthening of teeth; deep pocketsbetween the teeth and the gums (pockets are sites where the attachmenthas been gradually destroyed by collagenases); and loose teeth.

In 1999, a classification system was developed for periodontal diseasesand conditions, which listed seven major categories of periodontaldiseases, of which the last six are termed “destructive periodontaldisease” because they are essentially irreversible. In addition,terminology expressing both the extent and severity of periodontaldiseases are appended to the classes to further denote the specificdiagnosis. The extent of disease refers to the proportion of thedentition affected by the disease in terms of percentage of sites. Sitesare defined as the positions at which probing measurements are takenaround each tooth and, generally, six probing sites around each toothare recorded to make a determination of the extent of periodontaldisease. Typically, if up to 30% of sites in the mouth are affected, themanifestation is classification as localized; if more than 30% of sitesin the mouth are affected, the term generalized is used. The severity ofdisease refers to the amount of periodontal ligament fibers that havebeen lost, termed clinical attachment loss, and is defined by theAmerican Academy of Periodontology as mild (1-2 mm of attachment loss),moderate (3-4 mm of attachment loss), or severe (≧5 mm of attachmentloss).

Periodontitis also has been shown to have effects outside of the mouth.For example, periodontitis has been linked to increased inflammation asindicated by increased levels of C-reactive protein and Interleukin-6(IL-6). In addition, periodontitis has been shown to increase the riskfor a number of other diseases, including but not limited to, stroke,myocardial infarction, atherosclerosis, diabetes, osteoporosis, andpre-term labor.

The primary pathogen involved in periodontitis is Porphyromonasgingivalis, a gram-negative anaerobic bacterium. P. gingivalis inhibitsthe complement cascade, which usually converges at the third complementcomponent (C3) and leads to the generation of effector molecules thatmediate recruitment and activation of inflammatory cells via theanaphylatoxins, C3a and C5a, microbial opsonization and phagocytosis viaopsonins such as C3b, and direct lysis of targeted microbes via theC5b-9 membrane attack complex.

Currently, there is no satisfactory adjunctive therapy in periodontitis;antimicrobials and antibiotics have largely failed in that regard. Atpresent, perhaps the most promising approach is the use of agents thatpromote the resolution of inflammation (e.g., lipoxins and resolvins),although at least some of these agents appear to have stability issues(e.g., easily becomes oxidized and loses biological activity).

Methods of Treating or Preventing Periodontitis or Diseases Associatedwith Periodontitis

The mechanisms used by P. gingivalis to overcome and thwart the host'simmune response as described herein can be used against the pathogen inmethods of treating or preventing periodontitis or diseases associatedwith periodontitis. For example, blocking C3 effectively deprives P.gingivalis of crucial survival tactics. Thus, methods that inhibit orblock C3 expression, activity or activation can be used to reduce theamount of P. gingivalis in an individual, thereby protecting theindividual from periodontitis and associated systemic diseases likeatherosclerosis. In addition, methods that inhibit the immunosuppressivesignaling that occurs in the presence of C3 also can be used to reducethe amount of P. gingivalis in an individual, thereby protecting theindividual from periodontitis and associated systemic diseases.

Such methods (e.g., methods of inhibiting or blocking C3 expression,activity or activation) typically include administering a compound tothe individual that inhibits or blocks C3 expression, activity oractivation. By way of example, there are a number of compounds that areknown to inhibit or block C3 expression, activity, or activation (e.g.,C3 antagonists). For example, compstatin or analogs of compstatin,complement receptor 1-related gene/protein y (Crry), and complementactivation blocker-2 are inhibitors of C3 that are known in the art.See, for example, Sahu et al., 2000, “Complement Inhibitors TargetingC3, C4, and C5”, in Contemporary Immunology: Therapeutic Interventionsin the Complement System, pp. 75-112, Lambris and Holers, Eds., HumanaPress Inc., Totowa, N.J.; and Qu et al., 2012, “New analogs of theclinical complement inhibitor compstatin with subnanomolar affinity andenhanced pharmacokinetic properties,” Immunobiology, 218:496-505. Thecompstatin and compstatin analog sequences disclosed in the foregoingreferences are summarized in Table A above.

An antibody against C3 also can be used to inhibit or block C3expression, activity, or activation. Antibodies against C3 are known andare commercially available from, for example, CREATIVE BIOMART (Shirley,N.Y.), ABCAM (Cambridge, Mass.), and ACRIS ANTIBODIES (San Diego,Calif.). In addition, RNA interference (“RNAi”) can be used tospecifically target the nucleic acid encoding C3. RNAi is a process thatis used to induce specific post-translational gene silencing. RNAiinvolves introduction of RNA with partial or fully double-strandedcharacter into the cell or into the extracellular environment. Theportion of the target gene used to make RNAi can encompass exons butalso can include untranslated regions (UTRs) as well as introns. See,for example, Kim et al., 2008, Biotechniques, 44:613-6 as well as Lareset al., 2010, Trends Biotechnol., 28:570-9; and Pfeifer et al., 2010,Pharmacol. Ther, 126:217-27. See, also, Ricklin & Lambris, 2007, NatureBiotechnol., 25:1265-75.

In certain embodiments, one or more inhibitors of complement can beadministered to an individual and used to prevent or treat periodontitis(or diseases associated with periodontitis) via the role of complement,as described herein, in the formation of periodontitis and,specifically, in the establishment of P. gingivalis. Representativecomplement inhibitors include, without limitation, sCR1, C1 Inhibitor(C1inh), Membrane Cofactor Protein (MCP), Decay Accelerating Factor(DAF), MCP-DAF fusion protein (CAB-2), C4 bp, Factor H, Factor I,Carboxypeptidase N, vitronectin (S Protein), clusterin, CD59, compstatinand its functional analogs, C1q inhibitors or anti-C1q antibodies, C1inhibitors or anti-C1 antibodies, C1r inhibitors or anti-C1r antibodies,C1s inhibitors or anti-Cis antibodies, MSP inhibitors or anti-MASPantibodies, MBL inhibitors or anti-MBL antibodies, C2 inhibitors oranti-C2 antibodies, C4 inhibitors or anti-C4 antibodies, C4a inhibitorsor anti-C4a antibodies, C5 inhibitors or anti-CS antibodies, C5ainhibitors or anti-C5a antibodies, C5aR inhibitors or anti-C5aRantibodies, C5b inhibitors or anti-C5b antibodies, C3a inhibitors oranti-C3a antibodies, C3aR inhibitors or anti-C3aR antibodies, C6inhibitors or anti-C6 antibodies, C7 inhibitors or anti-C7 antibodies,C8 inhibitors or anti-C8 antibodies, C9 inhibitors or anti-C9antibodies, properdin inhibitors or anti-properdin antibodies, Factor Binhibitors or anti-Factor B antibodies, or Factor D inhibitors oranti-Factor D antibodies.

Compounds that inhibit or block C3 expression, activity, or activationcan be administered to an individual via any number of routes, whichtypically depends on the particular compound and its features. Compoundscan be incorporated into pharmaceutical compositions suitable foradministration to an individual. Such compositions typically include, atleast, the compound and a pharmaceutically acceptable carrier. As usedherein, “pharmaceutically acceptable carrier” is intended to include anyand all solvents, dispersion media, coatings, antibacterial andanti-fungal agents, isotonic and absorption delaying agents, and thelike, compatible with pharmaceutical administration. The use of suchmedia and agents for pharmaceutically active substances is well known inthe art. Except insofar as any conventional media or agent isincompatible with the active compound, use thereof in the compositionsis contemplated. Additional or secondary active compounds also can beincorporated into the compositions described herein.

A pharmaceutical composition as described herein is formulated to becompatible with its intended route of administration. Examples of routesof administration include parenteral, e.g., intravenous, intradermal,subcutaneous, oral (e.g., ingestion or inhalation), transdermal(topical), transmucosal, and rectal administration. In addition, localadministration into the periodontal pocket (e.g., via direct injection,or via, for example, a PERIOCHIP biodegradable chip) also is a route ofadministration that may be employed in the methods described herein.Solutions or suspensions used for parenteral, intradermal, orsubcutaneous application can include the following components: a sterilediluent such as water for injection, saline solution (e.g., phosphatebuffered saline (PBS)), fixed oils, a polyol (for example, glycerol,propylene glycol, and liquid polyetheylene glycol, and the like),glycerine, or other synthetic solvents; antibacterial and/or antifungalagents such as parabens, chlorobutanol, phenol, ascorbic acid,thimerosal, and the like; antioxidants such as ascorbic acid or sodiumbisulfite; chelating agents such as ethylenediaminetetraacetic acid;buffers such as acetates, citrates or phosphates and agents for theadjustment of tonicity such as sodium chloride or dextrose. The properfluidity can be maintained, for example, by the use of a coating such aslecithin, by the maintenance of the required particle size in the caseof dispersion and/or by the use of surfactants. In many cases, it willbe preferable to include isotonic agents, for example, sugars,polyalcohols such as mannitol or sorbitol, and sodium chloride in thecomposition. Prolonged administration of an injectable composition canbe brought about by including an agent that delays absorption. Suchagents include, for example, aluminum monostearate and gelatin. Aparenteral preparation can be enclosed in ampoules, disposable syringesor multiple dose vials made of glass or plastic.

Oral compositions generally include an inert diluent or an ediblecarrier. Oral compositions can be liquid, or can be enclosed in gelatincapsules or compressed into tablets. Pharmaceutically compatible bindingagents, and/or adjuvant materials can be included as part of an oralcomposition. Tablets, pills, capsules, troches and the like can containany of the following ingredients, or compounds of a similar nature: abinder such as microcrystalline cellulose, gum tragacanth or gelatin; anexcipient such as starch or lactose; a disintegrating agent such asalginic acid, PRIMOGEL (sodium carboxymethol cellulose), or corn starch;a lubricant such as magnesium stearate or Sterotes; a glidant such ascolloidal silicon dioxide; a sweetening agent such as sucrose orsaccharin; and/or a flavoring agent such as peppermint, methylsalicylate, or orange flavoring. Transmucosal administration can beaccomplished through the use of nasal sprays or suppositories. Fortransdermal administration, the active compounds typically areformulated into ointments, salves, gels, or creams as generally known inthe art.

It is especially advantageous to formulate oral or parenteralcompositions in dosage unit form for ease of administration anduniformity of dosage. Dosage unit form as used herein refers tophysically discrete units suited as unitary dosages for an individual toreceive; each unit containing a predetermined quantity of activecompound calculated to produce the desired therapeutic effect inassociation with the required pharmaceutical carrier. The dosage unitsthemselves are dependent upon the amount of compound to be delivered.The amount of a compound necessary to inhibit or block C3 expression,activity or activation can be formulated in a single dose, or can beformulated in multiple dosage units. Treatment of an individual with acompound that inhibits or blocks C3 expression, activity or activationmay require a one-time dose, or may require repeated or multiple doses.

Screening for Compounds that can be Used to Treat or PreventPeriodontitis or Diseases Associated with Periodontitis

The results described herein regarding complement component C3 and P.gingivalis also can be used to screen for therapeutic compounds (i.e.,compounds that inhibit the expression, activity, or activation of C3).For example, a nucleic acid molecule can be produced that includes apromoter operably linked to nucleic acid encoding a C3 polypeptide.Promoters that drive expression of a DNA sequence are well known in theart. Promoters suitable for expressing a nucleic acid encoding C3 areknown to those skilled in the art and include, for example, constitutiveor inducible promoters. Many constitutive and inducible promoters areknown in the art. As used herein, “operably linked” means that apromoter and/or other regulatory element(s) are positioned in a vectorrelative to a nucleic acid encoding C3 in such a way as to direct orregulate expression of the nucleic acid. Such a nucleic acid moleculecan be introduced into host cells (e.g., E. coli, yeast) using routinemethods (e.g., electroporation, lipid-based delivery systems,nanoparticle delivery systems, and viral-based delivery systems), andthe host cells can be contacted with a test compound. A vector asdescribed herein also may include sequences such as those encoding aselectable marker (e.g., an antibiotic resistance gene).

Methods of evaluating whether or not a test compound inhibits theexpression of C3 are well known in the art. For example, RT-PCR orNorthern blotting methods can be used to determine the amount of C3 mRNAin the presence and absence of the test compound. In addition, methodsthat can be used to evaluate whether or not a test compound inhibits theactivity or the activation of C3 are known in the art.

Methods of making recombinant host cells (e.g., recombinant mammalianhost cells) are discussed herein and are well known in the art. Inaddition, virtually any type of compound can be used as a test compoundin the screening methods described herein. Test compounds can include,for example and without limitation, nucleic acids, peptides, proteins,non-peptide compounds, synthetic compounds, peptidomimetics, antibodies,small molecules, fermentation products, or extracts (e.g., cellextracts, plant extracts, or animal tissue extracts).

In accordance with the present disclosure, there may be employedconventional molecular biology, microbiology, biochemical, andrecombinant DNA techniques within the skill of the art. Such techniquesare explained fully in the literature. The discovery will be furtherdescribed in the following examples, which do not limit the scope of themethods and compositions of matter described in the claims.

EXAMPLES Example 1 Mice Lacking C3 are Protected Against P.gingivalis-Induced Bone Loss

CS7BL/6 wild-type (WT) mice or mice deficient in C3 (C3^(−/−)) wereorally infected or not with P. gingivalis (Pg) and assessed forinduction of periodontal bone loss using defleshed maxillae (FIG. 1A).Buccal and lingual gingiva around the six maxilary molars were dissectedfrom the same mice and processed for real-time PCR to determine mRNAexpression levels for the indicated cytokines (normalized against GAPDHmRNA and expressed as fold induction relative to the sham-infected WTgroup) (FIG. 1B). Similar experiments were performed in which gingivawere homogenized and soluble extracts were used to determine cytokinelevels using LUMINEX-100 immunoassay detection technology (FIG. 1C).

It was found that mice lacking the central complement component C3(C3^(−/−) mice) are protected against Porphyromonas gingivalis-inducedbone loss relative to wild-type controls (FIG. 1). Inhibition of boneloss (FIG. 1A) correlated with diminished expression of inflammatory andbone resorptive cytokines (IL-1β, TNF-α, IL-6, and IL-17) at the mRNA(FIG. 1B) and protein (FIG. 1C) levels. These data conclusivelyimplicate C3 in destructive periodontal inflammation.

Example 2 Colonization and Effects of P. gingivalis in the Periodontiumof Normal or Complement-Deficient Mice

Wild-type (WT) mice or mice deficient in C3 or C5aR were orallyinoculated with P. gingivalis (Pg) or vehicle only (Sham) and weresacrificed 7 days later. The numbers of P. gingivalis and of totalbacteria in the periodontal tissue were determined using quantitativereal-time PCR of the ISPg1 gene (P. gingivalis) or the 16S rRNA gene(total bacteria).

Whereas P. gingivalis cannot colonize the periodontium of CSaR-deficientmice (C5ar^(−/−)), it can colonize the periodontium of C3^(−/−) mice andinstigate an increase in the total bacterial counts, as it does inwild-type mice (FIG. 2). Taken together with the data shown in FIG. 1,these findings suggest that, whereas dysbiosis is necessary forinflammatory bone loss, it is not sufficient by itself. Rather, thedysbiotic microbiota requires the presence of C3 to induce maximuminflammation and bone loss.

Example 3 C3^(−/−) Mice are Protected Against Ligature-InducedPeriodontal Bone Loss

Bone loss was induced through the use of a 5-0 silk ligature tied aroundthe maxillary second molar (L); the contralateral molar tooth in eachmouse was left unligated as baseline control (UC or WT).

This results in a P. gingivalis-independent model of periodontitis,resulting in massive local accumulation of bacteria and rapidinflammatory bone loss. C3−/− mice were protected in this model based onbone loss (FIG. 3A) and mRNA expression of the indicated cytokines (FIG.3B). Therefore, C3 is heavily involved in inflammatory bone losssuggesting that C3 inhibitors (e.g., compstatin) could find therapeuticapplication in periodontitis.

Example 4 Non-Human Primate Studies

The immune system and periodontal anatomy of the cynomolgus monkey isvery similar to that of humans, and ligature-induced periodontitis inthis NHP model displays bacteriological, immunohistological and clinicalfeatures that are most similar to those observed in human periodontitis.The cynomolgus monkey model is therefore considerably more predictive ofdrug efficacy in human periodontitis as compared to other, widely usedpreclinical animal models such as rodents. Moreover, the cynomolgusmodel of ligature-induced periodontitis allows longitudinal examinationof the disease in a way that cannot be performed in humans.

Silk ligatures were placed around maxillary posterior teeth (2^(nd)premolar and 1^(st) molar) on both halves of the mouth for a split-mouthexperimental design, i.e., one side was treated with active drug (Cp40,the current lead version of compstatin) and the other with inactiveanalog (control). Thus, each animal served as its own control. Aninitial study with a 6-week duration was conducted using two animals.Treatment with compstatin resulted in decreased clinical inflammationand bone loss (FIG. 4), as well as reduced levels of proinflammatorycytokines in the gingival crevicular fluid (GCF) and lower numbers ofosteoclasts in bone biopsy specimens (FIG. 5), as compared to controltreatments. Importantly, the decreased bone loss in sites treated withCp40 (revealed radiographically by greater bone heights, i.e., CEJ-ABCdistances; FIG. 4E) was consistent not only with decreasedosteoclastogenesis (FIG. 5G) but also with decreased GCF levels of RANKL(FIG. 5E), a key osteoclasto-genic factor. Moreover, the GCF levels ofosteoprotegerin (OPG), a natural inhibitor of RANKL, were maintained athigher levels in Cp40-treated sites than control sites during the courseof the study (FIG. 5F).

In a second NHP study, ligature-induced periodontitis was induced byplacing ligatures around the mandibular posterior teeth (i.e., in thelower jaw) of the same two animals plus in two additional animals (totalof four monkeys). The results obtained (FIGS. 6, 7, and 8) confirmed theresults of the original study. Moreover, the presence of four animalsallowed the possibility for statistical analysis. The protective effectsof Cp40 with regard to certain clinical parameters (PPD and GI, FIGS. 6Aand B) and most cytokine responses (FIG. 7) reached statisticalsignificance. Importantly, Cp40 caused a significant inhibition of boneloss (FIG. 8C), consistent with its effects on molecules regulatingosteoclastogenesis (decreased RANKL and increased OPG levels vs. controltreatment; FIGS. 7H and I, respectively).

This is the first time, for any disease, that complement inhibition hasbeen shown to inhibit inflammatory processes that lead toosteoclastogenesis and bone loss in NHP. Moreover, these data stronglysupport the therapeutic potential of Cp40 in human periodontitis.

Other Embodiments

It is to be understood that, while the methods and compositions ofmatter have been described herein in conjunction with a number ofdifferent aspects, the foregoing description of the various aspects isintended to illustrate and not limit the scope of the methods andcompositions of matter. Other aspects, advantages, and modifications arewithin the scope of the following claims.

Disclosed are methods and compositions that can be used for, can be usedin conjunction with, can be used in preparation for, or are products ofthe disclosed methods and compositions. These and other materials aredisclosed herein, and it is understood that combinations, subsets,interactions, groups, etc. of these methods and compositions aredisclosed. That is, while specific reference to each various individualand collective combinations and permutations of these compositions andmethods may not be explicitly disclosed, each is specificallycontemplated and described herein. For example, if a particularcomposition of matter or a particular method is disclosed and discussedand a number of compositions or methods are discussed, each and everycombination and permutation of the compositions and the methods arespecifically contemplated unless specifically indicated to the contrary.Likewise, any subset or combination of these is also specificallycontemplated and disclosed.

What is claimed is:
 1. A method of treating periodontitis in anindividual, comprising: (a) identifying an individual suffering from orat risk of developing periodontitis; and (b) administering to theindividual a composition comprising a pharmaceutically acceptablecarrier and a compound that inhibits or blocks C3 expression, activity,or activation, thereby treating the periodontitis; wherein thecomposition does not comprise an antibody, and wherein the compound is apolypeptide having an amino acid sequence as set forth in SEQ ID NO: 25.2. The method of claim 1, wherein the composition is administered by amethod selected from parenteral, intradermal, subcutaneous, oral, nasal,topical, transdermal and transmucosal.
 3. The method of claim 2, whereinthe composition is administered to the periodontal pocket of theindividual.
 4. A method of reducing the amount of Porphyromonasgingivalis and/or the inflammation caused by P. gingivalis in anindividual, comprising: (a) identifying an individual in which reductionin the amount of P. gingivalis is needed or desired; and (b)administering to the individual a composition comprising apharmaceutically acceptable carrier and a compound that inhibits orblocks C3 expression, activity, or activation, thereby reducing theamount of P. gingivalis in the individual; wherein the composition doesnot comprise an antibody, and wherein the compound is a polypeptidehaving an amino acid sequence as set forth in SEQ ID NO:
 25. 5. Themethod of claim 4, wherein the composition is administered by a methodselected from parenteral, intradermal, subcutaneous, oral, nasal,topical, transdermal and transmucosal.
 6. The method of claim 5, whereinthe composition is administered to the periodontal pocket of theindividual.